Consumers are interested in mitigating or delaying the dermatological signs of aging, such as fine lines, wrinkles, and sagging skin, and related conditions caused by the progressive degradation of the dermal-epidermal junction and of the cell-to-cell cohesion in the epidermis. Chronological aging, hormonal aging, and photo-aging each involve processes that degrade the three main protein components of skin: collagen, elastin, and fibrillin.
Collagen is the body's major structural protein, it supports tissues and organs and connects these structures to bones. Collagen plays a key role in providing the structural scaffolding surrounding cells that helps to support cell shape and differentiation. Elastin is a protein which give skin the ability to stretch and then snap back to its original state. Fibrillin is a glycoprotein, which is essential for the formation of elastic fibers found in connective tissue. Fibrillin is secreted into the extracellular matrix and becomes incorporated into the insoluble microfibrils, which appear to provide a scaffold for deposition of elastin. Collagen, elastin, and fibrillin are produced by fibroblasts, which are specialized skin cells located in the dermis. The stimulation of collagen, elastin, and fibrillin may improve the health and appearance of skin, as skin aging is generally associated with the loss of these proteins. There is a need in the art for compositions that retard skin aging, and which remediate the effects of skin aging.
microRNAs (miRNAs) are short ribonucleic acid (RNA) molecules, on average only about 22 nucleotides long and are found in all eukaryotic cells. miRNAs are believed to be post-transcriptional regulators that bind to complementary sequences on target messenger RNA transcripts (mRNAs), usually resulting in translational repression and gene silencing. If there is complete complementation between the miRNA and target mRNA sequence, the mRNA may be cleaved, leading to direct mRNA degradation. However, if there is not complete complementation, silencing is achieved by preventing translation. It has been estimated that the human genome encodes over 1000 miRNAs, which may target about 60% of mammalian genes and are abundant in many human cell types. However, to date, efforts to improve skin appearance and combat signs of aging, have not focused on the role of microRNAs.
It is therefore an object of the invention to provide compositions and methods for treating, ameliorating, inhibiting and/or preventing dermatological signs of aging.
It is another object of the invention to provide methods for treating, ameliorating, inhibiting and/or preventing dermatological signs of aging by modulating the levels of microRNAs that are related to the expression of collagen, elastin, and/or fibrillin in skin cells.
It is a further object of the invention to provide methods for identifying compounds that are useful for treating, ameliorating, inhibiting and/or preventing dermatological signs of aging, based on the ability to modulate the levels of microRNAs that are related to the expression of collagen, elastin, and/or fibrillin in skin cells.
The foregoing discussion is presented solely to provide a better understanding of nature of the problems confronting the art and should not be construed in any way as an admission as to prior art.